Minimizing power consumption in mobile devices is still important due to the nearly constant use of certain functionality of the mobile device even when in a battery-use mode. In many implementations, the camera of a mobile device, e.g., a cellphone, may have an actuator which moves one or more optical elements of a lens assembly to various positions that correspond to focusing the lens on a target scene. When the camera is not being used, the actuator can be configured to move the lens to a default position, for example, the infinity position.
A power source, for example a low voltage regulator (LDO), may be coupled to a display and a camera system (which may also be referred to herein as simply a “camera”), such that the power source provides power to both the display and the camera system. In some examples, the camera system includes a lens having at least one optical element, and an actuator which is coupled to the lens. The power source provides power to both the display and the camera system, such that the camera system will always be receiving power unless the power source is turned off. For example, when the display and the camera are both turned off (or are deactivated). Because the same power source always provides power to both the camera system (e.g., the actuator) and the display, when the display is on some power is still provided to, and consumed by, camera system even when the camera system appears to be turned off (or is not currently being operated to capture images). In such configuration, the actuator cannot be made to use no power because it is still receiving power. For example, even when a camera application on a cell phone is discarded and the camera application is no longer running, the camera will still be receiving power from the voltage regulator. For some components of the cell phone, including the actuator, the only way to control whether they receive and consume power is by activating or de-activating the voltage regulator supplying power to the component, that is, the actuator does not have another way to power down except to power down the voltage regulator. As a result, the actuator does not turn off but instead continues to consume power at least at a low level even when camera software (application) turns the camera off. This results in power consumption by the camera continuously even when the camera is off. The power consumption becomes negligible or zero only if the voltage regulator is powered down. Accordingly, improvements in such cell phones for minimizing the power usage of the camera would be advantageous.